Work will continue on studies on estrogen regulation of DNA synthesis in the rat uterus. DNA polymerases, a and B, will be assessed after estrogen treatment. Various estrogens are being used so that both early and late influences of estrogens can be monitored. Isolation and characterization of the specific uterine protein (IP) induced by estrogen will continue. It is hoped that antibodies can be used in some of this work. Studies on estrogen-receptor interaction with nuclear components will continue. Also we are interested in control of estrogen receptor levels themselves.